In connection with surgery for a number of diseases in the gastro-intestinal tract, one of the consequences in many cases is that the patient is left with an abdominal stoma, such as a colostomy, an ileostomy or a urostomy in the abdominal wall for the discharge of visceral contents. The discharge of visceral contents cannot be regulated at will. For that purpose, the user will have to rely on an appliance to collect the material emerging from such opening in a bag, which is later emptied and/or discarded at a suitable time.
An ostomy appliance may be in the form of a one-piece appliance for which a collecting bag for human body wastes is permanently, or fixedly, secured to an adhesive base plate for attachment to the human skin. Alternatively, the ostomy appliance may be a two-piece appliance comprising a base plate and a collecting bag which may be coupled to and uncoupled from each other through a coupling means. This has the effect that the base plate does not need to be separated from the skin of the user as often as exchange of the collecting bag requires. The base plate may need only to be changed every third or fourth day depending on the user, whereas the collecting bag may be changed more than once per day. Typically, it is desirable to need as few exchanges of the base plate as possible in order to reduce the risk of skin complications.
For two-piece appliances, the coupling means between the base plate and the collecting bag is typically either an adhesive coupling comprising an adhesive layer on the collecting bag or a mechanical coupling comprising cooperating coupling means on the base plate and the collecting bag. This invention relates to a mechanical coupling between the base plate and the collecting bag—and in particular to a locking ring for such a coupling.